1. Field of the Invention
The present invention concerns a magnetic resonance system of the type having a tool equipped with hall elements that allow the orientation of the tool to be determined relative to the direction of the basic magnetic field of the system.
2. Description of the Prior Art
Magnetic resonance systems are known that have a basic magnet that generates a static basic magnetic field that is essentially homogeneous within an examination volume, the basic magnetic field possesses a basic direction, and wherein the magnetic resonance system possesses an evaluation device and at least one tool that can be inserted into the examination volume and can be removed therefrom. It is known for the at least one tool to have (carry) a Hall element that is emits a binary signal that characterizes whether the basic magnetic field has a component that, relative to an element direction of the Hall element, is greater than a threshold. The Hall element communicates in terms of data with the evaluation device in order to transmit the binary signal that it emits. The evaluation device uses the transmitted binary signal to determine an orientation of the at least one tool relative to the basic direction and takes additional measures depending on this orientation.
In this known magnetic resonance system, the tool is normally fashioned as a surface coil. The threshold of the Hall element is so small that it is negligible in comparison with the basic magnetic field. Therefore the orientation within a semi-spherical solid angle range can essentially be detected by means of this known magnetic resonance system.
For some applications, however, the precision that can be achieved by the prior art is too coarse.